Combined screening and air separation of pulverulent material



COMBINED SCREENING AND AIR SEPARATION OF PULVERULENTMATERIAL Filed Nov. 7, 1945 1949- c P. MILLER I 2,477,935

7 nwz-wrpe CHIAREEIS PHILIP MILLER ATI'ORIVEX- Patented Aug. 2, 1949 COMBINED SCREENING AND AIR SEPARA- TION OF PULVERULENT MATERIAL Charles Philip Miller, Bingley, England, assignor to Keighley Laboratories Limited, England, a British company Keighley,

Application November 7, 1945, serial No. 627,143

In Great Britain November 24, 1944 This invention relates to the handling and purification of pulverulent material, as particuiarly exemplified by used case hardening or carburising compound such as granulatedcharcoal,

in which to pack the apparatus being treated.

As the carburising medium is used over and over again by incorporating a proportion of fresh compound to make up-losses it is necessary to avoid the introduction of foreign matter into the carburising medium during handling and it is necessary to free it from dust and inert matter in order to ensure a uniform carburisation.

Hitherto, handling, riddling. and picking out such impurities as burnt clay from the used carburising compound have always constituted major objections to the pack carburising process and when carried out by hand are both slow and dirty and,

involve considerable dust nuisance.

An object of the presentinvention is toprovide apparatus for the handling and purification of pulverulent material such as exemplified 2 Claims. (Cl. 209-23) 3 and 4 at the bottom. A flexible pipe 5 having a free end 6 is connected tangentially at 1 to the upper end of one of the hoppers, each of which are of round cross section.

A close fitting inverted cone 8 of perforated material having a. hole 9 at its apex is fitted inside the hopper at a point just below the entrance of the flexible pipe. A pipe in enters the top of the hopper and extends vertically downwards inside the hopper to a point adjacent to and but ashort distance above thehole in the cone. This pipe leads to a small chamber li on top of the other hopper 2, and open by used carburising compound by means of which the objections referred to previously are substantially eliminated.

According to the present invention apparatus for the handling and purification of pulverulent material such as used carburising compound comprises in combination, a closed chamber, an inverted conical sieve disposed within said chamber and having an outlet at its apex, a suction delivery pipe entering the chamber on one side of the conical sieve, a suction outlet pipe disposed with its only inlet opening on the same axis and in the same plane as the outlet in the apex of the inverted conical sieve and located adjacent to said outlet on the same side of the inverted conical sieve as the suction delivery pipe, and means disposed beneath the inverted conical sieve for emptying the chamber when required.

In one preferred form of the invention the inlet opening in the suction outlet pipe is provided with an adjustable shroud.

The invention will now be more particularly described by way of illustration with reference to the accompanying drawing which represents a diagrammatic sectional elevation of one pare ticular form of apparatus.

The apparatus consists of two hoppers I and 2, which can be emptied by close fitting valves at the bottom thereto. A second or outlet pipe l2 lea'ds out of this chamber at a point opposite to the entry of the first pipe, and is connected to a source of suction for example .a fan is and a dust-collector M if necessary. A grid or sieve I5 is placed in an inclined position across the chamber ii sothat material entering from the pipe Ill must passthrough it to reach the pipe l2.

The action of the apparatus is as follows: Suction is applied to the outlet pipe 12. Air enters the flexible pipe 5 the free end 6 of which is presented to the granulated material to be removed and cleaned. Air and the material pass up to the flexible pipe 5 and whirl round the material than fines and capable of further use is carried to the chamber I I. All material which is too large in size to pass the inclined grid i5 is deflected by the grid into the second hopper 2. -If the material is required to be graded into a number of sizes more hoppers similar to the second may be employed. The grading is efiected by using inclined grids of difierent mesh, the chamber with the finest mean grid being next to the outlet to the fan. Air and some fine dust passes through the outlet pipe to the fan.

The smalls and undesired heavy material are discharged from the first hopper as waste. The material in the second or subsequent hoppers'is good material, and when the suction is cut off, can be removed and used. 'In order to adjust the air separator at the bottom of the cone in the first hopper, an adjustable sleeve 16 may be fitted at the lower end of the vertical pipe, lowerins of this sleeve increases the suction and enables heavier material to be lifted.

'I declare that what I claim is: Y r

1. Apparatus for the handling and purification-oi pulverulent material such as used carburising compound, comprising in combination a closed chamber, an inverted conical sieve'disposed within said chamber and having an outlet at its apex. a suction delivery pipe entering the chamber on one side of the conical sieve, a suction outlet pipe disposed with its only inlet opening on the same axis and in the same plane as the outlet in the apex of the inverted conical sieve and located adjacent to said outlet on the same side of the inverted conical sieve as the suction delivery pipe and means disposed beneath the inverted conical sieve for emptying the chamber when required.

2. Apparatus for the handling. and purification or pulverulent material such as used carburising compound as -claimed in claim 1 in which the inlet opening in the suction outlet pipe is provided with an adjustable shroud.

CHARLES PHILIP mum.

REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Germany Apr. 11, 1929 

